| ¡¡ | Chinese Journal of Computers Full Text |
| Title | An Asynchronous Remote Mirror System Based on Storage Virtualization |
| Authors | XIANG Xiao-Jia YU Hong-Liang |
| Address | (Department of Computer Science and Technology, Tsinghua University, Beijing 100084) |
| Year | 2009 |
| Issue | No.10(1905¡ª1914) |
| Abstract & Background | Abstract Computerized data becomes more and more critical in today¡¯s digital life. Remote mirror can keep information systems alive with redundant hardware and software, even encountering site corruptions. Unfortunately, existing mirror systems have some limitations such as relying on specific storage devices, poor performance, and so on. This paper presents a storage virtualization based asynchronous remote mirror system. First, in this system, all data are protected by a logical container, that is, an asynchronous mirror logical volume, which can trace and transfer data updating automatically. This way, there is no device and driver dependency at all. Secondly, this paper presents an advanced non-stop mirror protocol to support seamless service switching when site corruption happens and automatic data recovery at rebuilding process after disaster. In addition, all the protocol can be executed on mirror IO nodes in SAN, introducing little overhead to the protected servers. Finally, it gives design on lock based concurrent access control mechanism for the asynchronous mirror logical volume. With the help of the lock, not only data consistency can be maintained, but also good concurrent read/write performance can be achieved. Experiments and evaluation results demonstrate that the prototype system has the ability to provide high reliability while only introduce little overhead: tolerated a site corruption while kept providing service, costing only 14% more time. Keywords asynchronous mirror logical volume; increment logical volume; primary/secondary sites |